To analyse if BCG treatment leads to long-term reduction of recurrence, progression, and cancer-specific mortality (CSM) in patients with high-risk NMIBC.

140 patients with high-risk NMIBC were drawn from a population-based cohort of 538 patients with newly diagnosed bladder cancer in the Stockholm County between 1995 and 1996. Data were collected prospectively, and a final follow-up for recurrence, progression, and CSM was performed after 15 years. Patients that received BCG were compared with patients who did not receive BCG. Survival analysis was done with Kaplan-Meier estimates and Mantel-Cox log-rank test. Multivariable Cox proportional regression with stepwise selection was performed to verify the statistical significance of clinicopathological factors of prognostic importance. Results were displayed in Hazard ratios and a p < 0.05 was considered to be statistically significant.

With a median follow-up of 100 months (2-182), 76 patients recurred; 50 progressed to muscle invasion; and 92 died of whom 38 died from bladder cancer. After 15-year follow-up, there was a statistically significant reduction in rate for recurrence (HR 0.40, p < 0.0001) and progression (HR 0.52, p = 0.038), but not for CSM, in patients that received BCG compared to those who did not.

In this group, BCG in high-risk NMIBC patients reduced the long-term risk of recurrence and progression. The effect on CSM is yet to be clarified.